The present invention relates to a structure for loading and unloading at least one ship for transporting a fluid, such as for example hydrocarbons, liquefied natural gas (LNG), liquefied petroleum gas (LPG) or any other liquefied gas.
The present invention applies in particular to the transfer of this type of product between a ship and a fixed structure consisting for example of a liquefaction unit or a regasification terminal when loading the ship, or a fluid reservoir when unloading the ship.
In view of certain constraints relating to safety and the movement of ships, it is preferable to carry out the fluid transfer operations while keeping the ship out of a port, in deeper waters, for example a few hundred meters away from the coast.
For carrying out such operations in open water, ship loading and unloading stations are known in particular which comprise a fluid transfer platform attached to the seabed by an attachment structure consisting of a set of piles driven into the seabed.
The platform supports articulated fluid transfer arms which are intended to be connected to pipe systems of the ship known as “manifolds” on the ship.
The known loading stations additionally comprise a set of mooring dolphins for absorbing the energy of berthing of the ship and the tide after berthing. The mooring dolphins are also attached to the seabed by rigid metal piles.
The fluid transfer platform is connected to a reservoir located on the coast or on a fixed platform at sea by a flexible conduit or pipeline that is partially or fully submerged.
This type of transfer platform requires a very large number of piles and is expensive and requires the use of heavy equipment for installation purposes.
Furthermore, due to their distance from the coast, this type of transfer platform is subject to the swell of the open sea and it is therefore necessary to orient them in such a way that, when the ship is moored at said platform, the ship faces towards the dominant swell. The “wind” factor must also be taken into account in the same way as the swell.
One aim of the invention is to propose a structure for loading and unloading at least one ship, which can be easily transported from a manufacturing site to the site of loading or unloading of the ship and can also be easily installed at this site, while withstanding waves of great height in extreme conditions.